Ganesha Purana is one of the minor Puranas. Ganesh Puran is believed to have been written between 11th and 14th century and is credited to the Ganapatya sect – who considered Ganesha as the Supreme Godhead.
The Purana extols that Ganesha is the creator, sustainer and destroyer of the universe.
It consists of 247 chapters and is divided into two parts. The first part contains information about worship of Ganesha. The second part details Ganesha as creator, protector and sustainer of the universe. The second part basically contains stories of Ganesha, his avatars and how he defeated the demons.
The first part is known as Upasana Khanda and the second part is known as Krida Khanda.
Ganesha Gita is also part of Ganesh Puran. In it, teachings of Ganesha on yoga, karma, bhakti and jnana are detailed. It is quite similar to Bhagavad Gita.